In a perfect world, a race car would always hook on any race track. It would go down the track straight, it would not rattle the tyres and it would not lose traction.

The trouble is, it is not a perfect world. We are dealing with a mechanical beast that operates under all sorts of different track and ambient conditions. Stuff wears out. Track conditions and weather conditions change during the day. And as a result, a problem with hookup can develop.

There are many factors involved when it comes to tuning a car and sorting out the race track. And with drag racing, there is not a lot of time to make adjustments.

But thanks to our pal Jerry Bickel, chief of Jerry Bickel Race Cars, we have a handy guide that can get you started on troubleshooting your traction issues. You might want to make a copy and paste it on your trailer door!

JERRY BICKEL RACE CARS TROUBLESHOOTING GUIDE

TYRE SHAKE

Possible Causes   –    Solutions

Clutch engagement too violent   –   Adjust clutch tension, weight, and finger height. Try a different clutch setup

Poor shock settings   –   Stiffen shock adjustments, replace worn shocks

Tyre pressure too low or too high   –   Adjust tyre inflation

Instant Center location moving   –   Add rear stabilizer bar

Instant Center too long or low/no tyre spin   –   Raise or shorten as required

Wrong weight distribution   –   Adjust weight distribution

Tyre shake on automatic car   –   Lower launch RPM, increase tyre pressure

CROOKED LAUNCH    

Possible Causes   –   Solutions

Tyre pressure unequal   –   Adjust tyre pressure evenly

Tyre rollout greater than 1/2″   –   Purchase matched tyres

Wheelie bar stagger incorrect   –   Adjust wheelie bar stagger

Preload incorrect   –   Adjust chassis preload

STRAIGHT LAUNCH BUT CROOKED OUT OF THE WATER BOX

Possible Causes   –   Solutions

Rear tyres have unequal load   –   Adjust corner weights (spring heights)

Incorrect chassis preload   –   Adjust chassis preload

NARROW TYRE TRACKS

Possible Cause   –   Solutions

Tyre spin   –   Improve traction, soften clutch adjustment, change launch RPM

CHOPPY TYRE TRACKS         

Possible Cause   –   Solutions

Tyres wadding up   –   Adjust tyre pressure, lengthen/raise Instant Center

SKIPPING TYRE TRACKS    

Possible Cause   –   Solution

Tyre shake   –   See Tyre Shake Section for solutions

STRAIGHT LAUNCH, POOR STARTING LINE TRACTION

Possible Causes   –   Solutions

Wheelie bars unloading tyres   –   Adjust wheel bar height, lower Center of Gravity and/or move CG forward

Poor tyre adhesion   –   Adjust tyre pressure, change to different tyre size and/or compound

Excessive power application   –   Adjust clutch, reduce flywheel weight, adjust launch RPM

POOR TRACTION AT SPEED OR DURING GEAR CHANGES       

Possible Causes   –   Solutions

Insufficient weight on rear tyres   –    Increase rear weight bias, add more wing angle

Excessive torque application   –   Soften clutch adjustment, revise transmission ratios

EXCESSIVE TYRE SQUAT (SIDEWALLS WADDING)

Possible Causes   –   Solutions

Tyre pressure too low   –   Increase tyre pressure

Chassis planting tyres violently   –   Adjust Instant Center longer/higher, stiffen rear shock rebound setting

EXCESSIVE CHASSIS SQUAT

Possible Cause   –   Solution

Instant Center too low   –   Raise Instant Center

DOWN TRACK PUSH/PULL IN ONE DIRECTION

Possible Causes   –   Solutions

Different size tyres   –   Equalize tyre inflation, check rollout

Rear end not square in chassis   –   Square rear end

Incorrect pre-load   –   Adjust 4-link pre-load

Front caster staggered   –   Adjust caster

Dragging brake or tyre   –   Check for brake drag, body/chassis contact with tyre

CAR WANDERS/DIRECTIONALLY UNSTABLE

Possible Causes   –   Solutions

Insufficient caster   –   Adjust caster

Too much toe-out   –   Adjust toe

Excessive bump steer   –   Check and correct bump steer

TRACTION AND/OR CONTROL LOSS OVER BUMPS

Possible Causes   –   Solutions

Instant Center too short   –   Lengthen Instant Center

Shocks too stiff   –   Adjust shocks

Front tyres too hard   –   Lower front tyre pressure

POOR REACTION TIME              

Possible Causes   –   Solutions

Front tyres too soft   –   Increase front tyre pressure

Slow chassis reaction   –   Loosen rear shock rebound setting, shorten/lower Instant Center

Clutch air gap too large   –   Adjust clutch air gap

Clutch engagement too soft   –   Adjust clutch

CHASSIS LOSES SETTINGS

Possible Cause   –   Solution

Components loose or worn   –   Check chassis and all components, repair and replace as necessary

SEVERE VIBRATION

Possible Causes   –   Solutions

Tyres out of balance   –   Balance tyres

Tyres shaking   –    See Tyre Shake Section for solutions

U-Joint misalignment   –   Check pinion angle and driveline alignment

Story by Wayne Scraba (with Jerry Bickel)

Photos by Wayne Scraba